Apparatus for the manufacture of paper



April 4, 1961 A. G. STOUT APPARATUS FOR THE MANUFACTURE OF PAPER 5Sheets-Sheet 1 Filed Feb. 19, 1959 April 4, 1961 A. G STOUT APPARATUSFOR THE MANUFACTURE OF PAPER 5 Sheets-Sheet 2 Filed Feb. 19, 1959 April4, 1961 A. G. STOUT APPARATUS FOR THE MANUFACTURE OF PAPER 5Sheets-Sheet 3 NQMM n I I I I l l lJllLl-l-l ll l Filed Feb. 19, 1959April 4, 1961 A. G. STOUT APPARATUS FOR THE MANUFACTURE OF PAPER 5Sheets-Sheet 4 iizvc/ziar jj/iwfi ga mm IW JG;

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: parts the I 2,971,686 a "APPARATUS FOR THE MANUFACTURE" or PAPERArthur G.Stout, Lincolnwood, 111., assignor to Jamar- Dlmen Company,MelrosePiuk, 111., a corporation of Illinois V The present inventionrelatesgenerally to an apparatus for the manufacture of paper butrelates moreqparticularlyto the drying aspects thereof.

; Inthe paper-manufacturing industry it is the conventional practice toform from the pulp stock a sheet or continuous web of materiahfl Theconventional papermaking machine comprises a drying section providedwith Patented Ap r. 4, 1961 web, passing through the drier section athigh speed,

A breaks, and'hencerequires instantaneous attention by the sociatedequipmentin order to permit the operator to prevent damage to themachine.

At times it is necessary to remove some of the doors for repair work orfor removing all of the doors and aspowerful vacuum and to provide anefiicient condenser a large number of internally heated drying rolls,the purpose of which-is to dry or evaporate the excessmoisture from the'web to a'predet ermined minimurn content. In a modern high-speedpaper-making machine it is necessary to evaporate thousands of poundsofwater per minwe in the form of water vapor and to conduct the same awayfrom the immediate vicinity of the drying section.

In order. better to control thefair conditions immediately surroundingthe drying section, it. has for. many years been the practice to providea canopy type hood which partially surrounds the drying section. Thistype hood comprises a roof and side, and end" walls which dependtherefrom, thus enclosing. thehprier pa'rtofthe drying section butleaving the lower part'ope'n. It has also been the practice to providesuitable fans to exhaust thewater vapor and lairmixture' and todischarge it to the outside atmosphere or to other processapparatuswhich will extract part of the heat. and water vaporpforpurposes of economy. Such constructions are. ofsome help in increasingeificiency but leave much to be desired. Ihere have also been,someinstallations wherein the drying section of the 'paper-niaking''machine has been fully enclosed; that is to say, such-hoods comprise aroof panel together with side auswhien reach rromthe' rooi In order topermit access to the drier section, especially firom the op'erativexsidetoffthe machine, some constructions have provided vertically movabledoors closingsubstantially the -lower halfl'of th'efsi'deQ wall. 'Ihesedoors, in operation, are horniallfloweredf and in'contact with themillfloor, the doors having relatively small observa-; tion windows topermit the operator to observe the dry-,, ing sectionf When itisnecessaryto haveaccessto'the drying rolls these doors must raised, ansforthis purpose it has been customary toprovideoperatingniechanismcomprising cables, line shafts, electric motor-simmingnirechanismsinwhich the doors can slide, and'many other patts,together with cont-ro lspermitting the raising'.

' of, either one or more" doors or the entire. group of doors 5-Themanner in which the above and 'otherobjects' to, maintain a "vacuumwithin the hood closure.

One of the objects of the present invention is to provide apparatus foruse in the manufacture of paper .for"

the purpose of dryingthfe paper and which, .while eflicient in'operation, will be of such construction that it can be produced,installed, and operated at relatively low cost,

and which will'enable the operator at all times to have.

full-and substantially unobstructedview of at least the lower part ofthe. operative part of the drier machine or of conventional paper-makingmachines.

Again itis an object of the invention to provide a novel apparatus forthe control of the air temperature and humidity conditions surroundingthe drier section of a" paper-making machine, which apparatus shall besimple in operation and effective in use.

A more specific object of the invention is to provide a closure for usewith a paper-drying machine or section which will provide means forsupplying the major portion cr me air for the drying operation to thedrier section from one or more sources and to provide a relatively highvelocity' air curtain on at least one side of the machine, the aircurtain being blown across an opening between the mili-floorand thelower margin of at least one of the closures side walls, together withmeans'for exhausting from the upper interior portion of the closure allthe air supplied to the closure, together with the-water-vaporresultingfrom the drying operation, and to maintain such balance in thespace within the closure with that'of the mill area exterior of'theclosure as to prevent more'than arelatively small amount of jairflowin'g from the millfinto' said closure through'the aircurtain.

fate the drying operation. A

quantityof air supplied to the closure is heated togfacili a attainedwill appear as the specification proceeds.

that formithej bottom clqsurelf or one side of the" drying Such a fullyenclosed the partially enclosed ho'jod earlie conditionof the spacewithin o d inay However, becausepf the number and complexity of the" ity devices, there 1s always danger oithes ihitial, cost [is]relatively'high Furthermore, ql 'i l F F b 'ffi I ,:;The inventionwi-llbe particularly described inconneo tion'with a typical dryingsection of a high-speed papermaking machine but this, it should beunderstood, is-by way of illustrationyand not by way 'of lirnitationsincel the invention may be used with advantage in other types-,ofipaper-drying machines in ,themanufactureof paper."

"In the drawings: Y r

removal and v LA st'll further objector the invention 'l S fC I provideclosure means of the kind described, wherein .thernajor.

figure; 1 is as diagra H 7 atio .view in perspective elevav p of thatportionofthe closure strncturewhich extends oye th:'l1lill;1fl 00l,theisamebeing shown in its relation to; the drying section of apaper-making machine. i it Fig, 2, isiatransverseaverticalsectional.view substam i tially on the, linezrazotfigrtbuton a somewhat largerscale and also showing part of theapparatus which is disposed in space underlying the mill floor.

Fig. 2A is a fragmentary transverse vertical section similar to theupper portion of the left-hand sideof Fig. 2 but illustratinga modifiedconstruction.

Fig. 3 is a transverse longitudinal section substantially on a line 3-3of Fig. 2, viewed in the direction of the arrows but upon a smallerscale.

Fig. 4.is a view similar to Fig. 3 but taken along the line -44 of Fig.2.

Fig. 5 is a fragmentary view on an enlarged scale of a part of the millfloor, a portion thereof being broken away to show one of the blowerelements which is used tosupply high velocity air to discharge openingsin the mill floor to constitute a substantially continuous air curtainextending across the open area below the bottom portion of one of theclosure side walls and the mill floor."

Fig. 6 is a perspective view of a blower unit air trunk section, anumber of which can be provided for supplying the high velocity air toconstitute the substantially continuous air curtain.

Fig. 7 is a view in elevation substantially on the line 7-7 of Fig. 2,but on a smaller scale, showing a modified construction in which the aircurtain arrangement is omitted from that side of the machine.

Fig. 8 is a fragmentary view of one end of a drying roll showing amodified feature, and

Fig. 9 is a view on the line 9--9 of Fig. 8.

General description of the invention There is involved a paper-dryingmachine which, in practice, is a section of a paper-making machine. Thepaper web, as it leaves the wet end of the paper-making machine, entersthe drier section, there passing over a considerable number of hot rollsusually heated by steam admitted to the interior of the rolls. The driedweb leaves the opposite end of the drier section in accordance withknown practice.

The present invention in one form comprises a closure for thepaper-drying section and includes a roof portion, end walls, and sidewalls which depend from the lower outer marginal portions of the roofportion, terminating at a level substantially above the mill floor, thusproviding openings at each side of the machine extending substantiallythe entire length of the drying section.

This arrangement permits continuous observation of the drying machine.Passages are always available for the operator to gain instant access tothe machine should conditions so require.

Means are provided to exhaust from the upper portion of the closure, asby power-driven and controlled exhaust fans, the large volumes of airwhich enter the closure for paper-drying purposes as well as thesubstantial volume of water vapor resulting from the dry ing operation.

"ln the illustrated form of the invention the drier section comprises amajor portion which extends above the mill floor, and a minor portionlocated below the mill floor, there being an opening through the millfioor over which the major portion of the drier section is positioried.

Below the mill floor there is provided blower means for supplying amajor part of the air to the drier section together'with means forheating this air prior' to its passage through the mill floor opening,thereby increasing the drying capacity of the air. v

Asshown, the'said blower means is arranged to dis charge into what'maybe termed a plenum chamber formed by two end wallsa'nd two side walls,th e latter extending the full distance between the end walls.- All ofsaidfwalls' extend from the underside of the'mill' floor textilenextmtieor below-or some other floor-like struc-' ture serving to closethe bottom of the so-called plenum chamber.

Additionally, the invention comprises means for establishing andmaintaining a substantially continuous air curtain located at each sideof the drier section of the machine extending substantially the entirelength thereof and flowing upwardly so as to traverse the openingbetween the lower marginal portions of the closure side walls and themill floor.

In the form of the invention illustrated, the air curtain is provided bya plurality of motor-driven blowers connected to discharge high velocityair through a plurality of slots in or .adjacent the mill floor andextending longitudinally of the closure below the side walls of theclosure. Means are provided whereby the air forming the air curtain isheated to aid in effecting the web-drying operation.

In the form shown the major part of the air for drying purposes flowsthrough the opening in the mill floor and, while large in volume, is ofrelatively low velocity as compared with the air discharging from theslots to form the air curtain; that is to say, the air discharging fromthe slots to form the air curtain is of relatively high velocity and ofrelatively low volume as compared to that of the major air flow.

Means are also provided to control the volume of air and moisture vaporexhausted from the closure per unit of time, which is obviously relatedto the conditions within the closure, the same being dependent upon thespeed of the web passing through the drier section, the amount ofmoisture in the web, the amount to be evaporated by the drier, etc.

Means are also provided for the control of the amount, volume, andvelocity of the air supplied by the blower means which furnishes themajor part of the air as well as that supplied to produce the aircurtains.

The various means for supplying air to and removing it and the watervapor from the closure are operatively controlled to maintain suchbalance inwardly and outwardly of the closure as will prevent more thana relatively small volume of air from passing through the air curtains.

In a modified arrangement the closure is provided with an air curtainonly on one side, the other side being closed from the roof portion tothe mill floor and being provided with sliding doors to permit access tothe drying machine.

There are further details and modifications but the foregoing generaldescription will facilitate an understanding of the invention.

Further and more detailed description of the invention With particularreference to Figs. land 2, the closure comprises roof section 20.longitudinal side walls 21 and 22, and end wall portions 23 and 24,which parts are mounted over and preferably supported by steel frameworkS connected to and extending from the upper part of the machine frame F.

The drying machine shown is typical of the drying scction of ahigh-speed paper-making machine. It comprises The roof was 20 issubstantially equa in length to that of the'machine and'is" greater'inwidth; thus pr'oviding' portions which extend beyond themachine at eachside. The'side walls 21 and'22 are'substantiallycoextensive'in lengthwith the met 20; and extend 'from" access by the operators to the and 6.

afo'imse r the roof, eaves, or side marginal portions downwardly to aplane substantially halfway between the roof, caves, and the mill floor,thus providing an elongated substan-' tially rectangular area extendingfrom one end wall to the other 'end wall. This opening, as clearlyappears in Fig. 1, provides an unobstructed view of the lower part ofthe drying machine and also provides for the'unobstructed l area closelyadjacent the drier machine side frames. V The'structure thus describedprovides enclosure for the top and apartial closure for the sides of themachine, to gether with closures formed by the opposite end walls, whichextend from the roof downwardly to the mill floor, except-for transverseopenings necessary to permit entry and exit of the paper web to and fromthe drying machine. Communicating with the upper portion of the closureis a plurality of exhaust ducts 30, each connected with a motor operatedexhaust fan 40 and serving as means for exhausting air'and vapors fromthe upper portion of the closure. .7 or V Since it is desirable thatthemajor partof the airfor drying purposes be supplied to the closure underproperly controlled conditions, means are provided for that purpose. 2Means for supplying major part of air to machine closure The means, hereshown for supplying the major part ofthe air for drying purposeswillbebest understood by reference to Figs. 2 and 3, wherein SF represents asub-floor located a subtsantial distance below the mill floor M.Extending between the bottom side of the mill floor M and thesub-floorSF are four upright walls, i.e., two end walls 42 and 43'and two sidewalls 44 and 45, the latter extending from end wall to end wall (seeFig. 3.)'and thus forming, with the sub-floor SF, the mill floor M, andthe opening 0 an open top chamber AC communicating with the driersection which extends above the Ashere shown, the side walls 44 and 45are spaced outwardly of the vertical structural members 50 which supportthe drying machine. Since the drying machine is ormay be of conventionalconstruction, parts thereof are shown" only'by broken lines which willsuflice to indicate the relationship of the machine to theclosure andassociated mechanism: 1 g

' In order to permit access to the chamber AC the side walls areprovided withza plurality of doors 51.

1 Forsupplying a major part of the air for drying purposes,'there'is'provided a pluralitly'of blowers 53,. each driven byaseparate electric inotor 54;

In order to provide heated air for discharge by thebloW- ers 53,aiheater 55 is provided and which communicates withthe blowerintake.By:.the described means .a large volume of'heated. air is supplied to;the chamber AC un derlyingthe mill floor and-tothat part of the dryingma- 6 which supply the air to the chamber, it is"obviou's the airdischarging from the tubes 64, which are positioned to extend into theslots 60 in the millfloor, will also be heated. If desired, separatemeans can be provided to supply heated air to the ducts 61.

By making the ducts in sections, the air supply can be controlledindividually to each section by means which will be described later. -'Ihese'sections .alsofacilitate. adapting the air supply to the varyingstructural features of the building.

The velocity of the air discharging from the-slots to form the aircurtains is relatively high; that is to say, the velocity is muchgreater than that of the air flowing through the opening 0 and whichprovides the major portion of air for drying purposes.

Modified means for providing air curtain In some instances, particularlyin old installations, the structural arrangement of, the mill may besuch ass-to preclude the locating of the air ducts below the mill floor.InFig. 2A there is shown an arrangement wherein the elongated. air duct61M is located above the mill floor and adjacent the machine frame. Itis proivded with a plurality of adjustable air discharge tubes 64Marranged to form an air curtain as before described. It will, of course,be understood that means are provided to supply ,air to the duct 61Munder pressure as required t form the high velocity air curtain.

Modification in which one side of machine is fully closed 1 quick accessis necessary inan emergency; When.the

chine which extends upwardlyofirthe millfioor through V theinillflooropening"0..

Iheapparatus for providing the dir curtains .'This" apparatus will bebest understood by refer'enceto .willbe observed in Figs 1,2, and4,there ispro vided in the mill. 11001 M a plurality of slots whichextend longitudinally b'elowthe side walls of the closure.

.PrferablyLthere. is provided a plurality of airtrunk'sectailingFigaosfagEach section comprises a duct 61, a blower 62-;and ian 'electric'xmotor. '63. for operatingthe (blower:

Thelblower discharges intoth'e 'duct 61, theairdischarg- *ing 'upwardlythroughawplurality of relativelyinarrow tubes' 64; each of which' isprovided with'aydamper 65 to controlthe direction ofzflow ofjthedischarged air. i

open area is provided along one sideonlyand the air curtain thereestablished and maintained,.t;he side wall on the other'side of themachine is extended to the mill. floor. Such an arrangement is shown inFig. 7. i p

In this instance the one side wall is provided a plurality. ofhorizontally sliding doors in theupper part of the side wall and aplurality of horizontally jsliding doors 71 in' the lower part; Bysliding the. door 1o 5: gitudinally of the side wall, accessrna'ybe,gained. to any part of that side of the machine. Since the oppositesideofthe machine is providedwith an openlowerfara' traversed by anair'curtain as-before described, it is obvious thataccess can be hadcontinuously to-that side of the machineas well as the ability toobserve thee'ntire .lower part of that side of'the machine" during operafionh. v M V I The modification shownin Figs. 8 and 9 I It will beappreciated that. thedrying rolls are highly heated. Hence some of theradiant heat from. the por= 65' der journals having a bearingin theframe to permit the tions inoperative alignment, one 'of which is shownin de- 0. can be. put iniplaice and'clampedby'means of-fthe the; end ofcylinder. by means o f a plurality of circumferentially spaced legport1ons'85; showmthe disc. 831 is. provided iwith'i a new,

air openings 86 and a'plurality of radial vanes 87'so' that, in therotation of the cylinder, air is caused to circulate in the'spacebetween the cylinder end and the confronting face of the disc.

The disc 83 is preferably made of a bright metal, such asstainlesssteel, and the face confronting the end of the cylinder 80 is preferablyprovided with a black coating 88 for heat-absorbing purposes.

Conveniently, the disc may be provided with a manhole member 89positioned over the usual manhole cover usually found in the end of thedrier rolls.

The control panel Referring to Fig. 1, there is provided preferablyadjacent one end wall of the drying machine closure an electricalcontrol board or panel 90. This control board contains a plurality ofswitches 92 wired and connected to control the various motors foroperating the blowers which supply the major part of the air for dryingpurposes, the motors which operate the blower, which supply the highvelocity of air to establish and maintain the air curtains, and themotors for operating the exhaust blowers. The electrical arrangement issuch that any or all motors operating the blowers for supplying themajor part of the air can be started or stopped at will; also,

any or all of the motors for operating the blowers providing the highvelocity air for the air curtains can be started and stopped at will,and the like control is provided for the motors that operate the exhaustfans.

The operation of the various motors, the electrical controls therefor,and the positions of the dampers or other means governing the velocityand volume of air discharging into the closure, and the air and vaporexhausted from the closure is such that a substantial balanee ismaintained within the closure and in the mill adjacent the side walls sothat not more than a relatively small amount of air can pass through theair curtain. In practice,- it may be advisable to permit a relativelysmall amount of air to pass through or into the air curtains to assureagainst the discharge of moist air from the drier into the adjacentportions of the mill.

The air curtain air, as it passes upwardly, preferably strikes the solidinner side wall of the closure just above the lower marginal portionthereof and, because of its high velocity, will tend to follow along theinner side face for. some distance. This, to a certain extent, acts asan insulator and, in any event, prevents the curtain air from passinginto the mill area outside the closure.

I claim:

1. Apparatus for use in combination with a paper-drying machine havingat least a substantial portion extending upwardly of a mill floor, saidapparatus comprising a roof extending over the top of the machine andbeing of greater width than at least that portion of the machine whichextends upwardly of the mill floor so that the roof extends beyond eachside of said last-mentioned portion ofthe. machine, end walls positionedat the ends of the the said roof and joining said end walls at each end,at least one of said side walls extending from adjacent the.

outertmarginal side portion of the roof and terminating in a planesubstantially above the mill floor, 'therebyproviding anopenarea'between the' lower margin of that side wall and, the. mill floorwhich issubstantially coextensive in length with that of the'saidsidewall, means for supplying air at relatively high velocity, airoutlet-a means positioned longitudinally of! the saidside wallssubstantially coextensive. in'length with the said open area, beingadjacentthe mill .fl'oor and being arranged to"dis-- chargeairupwardlyin the form of an aircurtain means communicatingsaidlair-su'pplying means with said air. outletimeahs whereby thecurtain'of'a-ir' moves' at relatively high velocity across said openarea in a direction to pass inwardly of the outer face of the adjacentside wall, other means for supplying a major part of the drying air tothe machine, means for exhausting from the upper interior portion of theroof and walls air supplied by said major air-supplying means and theair supplied to form said air curtain together with the water vaporresulting from the drying operation, all said means being formed andadapted to supply air in such volume and velocity as to maintain such abalance between the space within and the air forming outwardly of saidopen area below the side walls that the air passing out the exhaustmeans is comprised mainly of that supplied by said major air-supplyingmeans and said curtain.

2. The arrangement set forth in claim 1 together with means for heatingthe major part of the drying air.

3. The arrangement set forth in claim 1 together with means for heatingthe air forming the air curtain.

. 4. Apparatus for use in combination with a paper-drying machine havingat least a substantial portion extending upwardly of a mill floor, saidapparatus comprising a roof extending over the top of the machine andbeing of greater width than at least that portion of the machine whichextends upwardly of the mill floor so that the roof extends beyond eachside of said part. of the machine, end walls positioned at the ends ofthe roof, one end wall having an opening to provide for the entry of theweb to the other and an opening for the exit of the web passing from themachine, longitudinal side walls substantially coextensive in lengthwith the said roof and joining said end walls at each end, said sidewalls extending from adjacent the outer marginal side portions of theroof to a plane substantially above the mill floor, thereby providing anopen area between the lower margin of each of the side walls and themill floor which is substantially coextensive in length with that of theside wall blower means, air slots positioned below and longitudinally ofthe said side walls substantially coextensive in length with the saidopen area, being adjacent the mill floor and being arranged to dischargeair upwardly, means communicating said blower means with said air slots,means for actuating said blower means whereby air at relatively highvelocity in the form of an air curtain, is blown across each said openarea in a direction to pass inwardly of the outer face of the adjacentsaid side wall, other means for supplying a major part of the drying airto the machine, means for exhausting from the upper interior portion ofthe closure formed by the roof and walls the air supplied by said majorair-supplying means and that supplied to form said air curtain togetherwith the water vapor resultingfrom the drying operation, saidair-supplying means being formed and adapted to supply air in suchvolume and velocity as to maintain such a balance between the spacewithin the side walls and air curtains and that outwardly thereof aswill prevent the flow of more than a relatively small volume of air fromthe mill into said closure through the areas covered by said aircurtains. V a

5. The arrangement set forth in claim 4 together with means for heatingat least the major part of the drying air.

6. Apparatus for use in combination with a paper-drying machine havingat least a substantial portion extending above a mill floor, saidportion being positioned over an opening in the mill floor communicatingwith an underlying area, said apparatus comprising a roof. extendingover the'top of that portion of the paper-drying machine which extendsabove themill floor and being of'greater widththan said machine portionso as to extend beyond each side thereof, end'walls positioned at theends of the roof, one end wall havingan opening to provide for the entryof the web to and the other an'opening for the exit ofthe'web passingfrom the machine, longitudinal side wallssubstantiallycoextensive inlength with the said roof and joining said endiwalls at each end, saidside .wallsextending from adjacent the outer marginalside' portions ofthe roof to a plane substantially above the mill floor, therebyproviding an open area between the lower margins of the side walls andthe mill floor, which is substantially coextensive in length with thatof the side walls, blower means, air slots positioned below andlongitudinally of the said side walls being adjacent the mill floor andbeing arranged to discharge air upwardly, means communicating saidblower means with said air slots, means for actuating said blower meanswhereby at relatively high velocity in the form of an air curtain isblown across said open areas in a direction to pass inwardly of theouter side of said side walls, means for supplying the major portion ofthe drying air to the machine through said first mentioned flooropening, means for exhausting, from the interior portion beneath theroof, the air supplied to the machine through said mill floor openingand by said air forming the air cur-,

tains together with the water vapor resulting from the drying operation,said air-supplying means being formed and adapted to supply air in suchvolume and velocity as to maintain a balance between the space inwardlyof the curtains and walls and that outwardly of said open area below theside walls as will prevent the flow of more than a relatively smallvolume of air from the mill in a direction to be discharged by saidexhaust means.

7. The arrangement set forth in claim 6 together with means for heatingat least the major part of the drying air.

8. The arrangement set forth in claim 6 in which the means for supplyingthe major part of the drying air comprises a chamber underlying the millfloor opening at the top into said mill floor opening and includingblower means for discharging air into said chamber for passage throughsaid floor opening.

9. Apparatus for use in combination with a paperdrying machine having atleast a substantial portion extending upwardly of a mill floor, saidapparatus comprising a roof extending over the top of the machine andbeing of greater width than that portion of the machine which extendsupwardly of the mill floor so that the roof extends beyond each side ofsaid portion of the machine, end walls positioned at the ends of theroof, one end wall having an opening to provide for the entry of the webto the machine and the other an opening for the exit of the web passingfrom the machine, longitudinal side walls substantially coextensive inlength with the said roof and joining said end walls at each end, one ofsaid side walls extending from adjacent the outer marginal side portionsof the roof substantially to the mill floor and the other to a planesubstantially above the mill floor, the latter thereby providing an openarea between its lower margin and the mill floor which is substantiallycoextensive in length with that of the superposed side wall portion,blower means, air slots positioned beupper interior portion of theclosure formed by said.

roof and walls the air supplied by said major air-supplying means andthat supplied to form said air curtain together with the water vaporresulting from the drying operation, said air-supplying means beingformed and adapted to supply air in such volume and velocity as tomaintain such a balance between the space Within the closure and thatoutwardly of said open area below the said side wall as will prevent theflow of more than a relatively small volume of air from one side of theopen zone between the lower margin of the side wall and the mill floorto the other.

10. The arrangement set forth in claim 9 in which the major portion ofthe drying machine is positioned over an opening in the mill floorcommunicating with an area below and the major portion of the air fordrying is supplied through that opening.

11. The arrangement set forth in claim 9 in which means is provided forheating at least the major portion of the air supplied to the dryingmachine.

12. The arrangement set forth in claim 9 in which means is provided forheating at least the air supplied to form the air curtain.

13. The arrangement set forth in claim 9 in which the means forproviding the air curtain comprises a number of operative sections andmeans for actuating all or any part thereof.

14. The arrangement set forth in claim 10 which includes an open topchamber underlying the mill floor opening with the open top thereofcommunicating the chamber space with the closure space formed by the topand side walls, and blower means forcing air into the said chamber tosupply the major portion of the air for drying purposes.

15. The arrangement setforth in claim 10 which includes an open topchamber underlying the mill floor with the open top thereofcommunicating the chamber space with the said closure space, and blowermeans located in said chamber space and having structure discharging airupwardly through the mill floor to provide the said air curtain.

16. Apparatus for use in combination with a paperdrying machinecomprising a plurality of heated drying rolls and having at least asubstantial portion extending upwardly of a mill floor, said apparatuscomprising a roof extending over the top of the machine and being ofgreater width than that portion of the machine which extends upwardly ofthe mill fioor so that the roof extends beyond each side of said portionof the machine, end walls positioned at the ends of the roof, one endwall having an opening to provide for the entry of the web to themachine and the other an opening for the exit of the web from themachine, longitudinal side walls sub stantially coextensive in lengthwith the said roof portion and joining said end walls at each end atleast one of said side walls extending from adjacent the outer marginalside portion of the roof and terminating in a plane substantially abovethe mill floor, thereby providing an open area between the lower marginof the said side wall and the mill floor which is substantiallycoextensive in length with that of the side wall portion blower means,means for blowing air at relatively high velocity across said open areain a direction to pass inwardly of the said side wall, therebyestablishing an air curtain across that area, means associating the endsof those drying rolls located in the said open area for intercepting atleast a part of the radiant heat from the rolls to prevent the same frompassing through said air curtain into the mill.

17. The arrangement set forth in claim 16 in which the means forintercepting at least a part of the radiant heat from the rollscomprises a disc of bright metal, spaced from one end of the roll andhaving the one face confronting the end of the roll, the said face beingsubstantially black.

References Cited in the file of this patent UNITED STATES PATENTS UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 2,977 686 IApril 4, 1961 Arthur G. Stout It is hereby certified that error appearsin the above numbered patent requiring correction and that the saidLetters Patent. should read as corrected below.

Column 8, line 11, strike out "the air forming! and Insert the sameafter :"and" in line 14, same column.

Signed and sealed this 3rd day of October 1961,

I (SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of PatentsUSCOMM-DC

